There is a need for safe, effective antibacterial and anti-inflammatory agents for use in oral care compositions. Magnolia extract is known to contain compounds having antibacterial and/or anti-inflammatory properties, and such compounds have been the focus of considerable interest for use in oral care compositions. The use of such compounds in oral care compositions is described, for example, in WO2001/085116, WO 2011/106492 and WO 2011/106493, the contents of which application are incorporated herein by reference. Methods of synthesizing magnolol (5,5′-diallyl-biphenyl-2,2′-diol) are disclosed, e.g. in WO 2011/106003. Synthetic non-natural analogs of various components of magnolia extract having other alkyls in place of allyl are also known to have antibacterial activity, but the compounds are in some cases expensive or difficult to synthesize.
Existing synthetic methods for magnolol involve costly reagents and yields are low. There is a need for cheaper, higher yield synthetic procedures to make magnolol and related compounds.